Effect Of Amniotic Fluid Volume In The Last Trimester Of Pregnancy On Delivery Mode And Neonatal Outcome

Objectives To explore the effect of different amniotic fluid volume on delivery mode and neonatal outcome during the last trimester of pregnancy.Methods Using a retrospective cohort study,3501 parturients were enrolled in the obstetric hospital of Hebei general hospital from January 2018 to April 2019.According to the inclusion exclusion criteria,1435 cases were excluded and 2066 cases remained.According to the amniotic fluid index,293 cases were divided into?8.0cm group(amniotic fluid decreased group)and 1773 cases were divided into 8.0<AFI<25.0cm group(normal amniotic fluid group).The general data of the two groups were compared.According to the amniotic fluid index,the patients were divided into 5 subgroups: ?5.0cm group(oligohydramnios group),51 cases;5.0<AFI?8.0cm group(borderline oligohydramnios group),242 cases;8.0<AFI?12.0cm group(normal amniotic fluid group 1),563 cases;12.0<AFI?20.0cm group(normal amniotic fluid group 2),1152 cases;20.0<AFI<25.0cm group(normal amniotic fluid group 3),58 cases.The clinical indexes of amniotic fluid decreased group were compared with normal amniotic fluid group and 5 subgroups: delivery mode(vaginal spontaneous delivery,selective cesarean section,labor induction,instrumental delivery and transfer to caesarean section),general outcome of newborn(birth weight,Apgar 1 minute score,neonatal admission and hospitalization time of NICU)and neonatal complications(Neonatal aspiration syndrome,neonatal brain injury,neonatal infection,metabolic acidosis and respiratory distress syndrome).The database was established by Excel software,and the statistical data were analyzed by SPSS 21.0.The measurement data were expressed by median and quartile spacing,Mann Whitney rank sum test;the counting data were expressed by composition ratio,chi square test or corrected chi square test;the relationship between amniotic fluid volume,delivery mode and neonatal outcome was analyzed by multivariate logistic regression,and the age,gravidities,parities,BMI,gestational weeks,hypertensive disorders during pregnancy and diabetes mellitus were adjusted.RR and 95% CI were used to evaluate the effect of amniotic fluid volume,delivery mode and neonatal outcome.P<0.05 was statistically significant.Results Through the comparative analysis of amniotic fluid decreased group,normal amniotic fluid group and five subgroups,it was found that there were statistically significant differences between amniotic fluid decreased group and normal amniotic fluid group in vaginal spontaneous delivery,labor induction,selective cesarean section and referral cesarean delivery(P<0.05),and there was no statistically significant difference in instrument delivery(P>0.05).Compared with oligohydramnios group,borderline oligohydramnios group and normal amniotic fluid group,with the increase of amniotic fluid,the rate of vaginal spontaneous delivery increased,and the rate of transfer to caesarean section decreased(P<0.05);the rate of labor induction in borderline oligohydramnios group was the highest,followed by oligohydramnios group,and the rate of labor induction in normal amniotic fluid group was the lowest(P<0.05).There was no significant difference in delivery mode among the three normal amniotic fluid subgroups(P>0.05).The rate of neonatal admission and hospitalization time of NICU in amniotic fluid decreased group were higher than those in normal amniotic fluid group(P<0.05).Compared with the five subgroups,the more amniotic fluid,the higher birth weight(P<0.05);the lowest rate of neonatal admission was in normal amniotic fluid group 1,and the highest in group with oligohydramnios group(P<0.05).Compared with the normal amniotic fluid group,the difference of neonatal aspiration syndrome,brain injury,infection and respiratory distress syndrome was statistically significant(P<0.05);there was no statistical difference in neonatal metabolic acidosis(P>0.05).Compared with oligohydramnios group,borderline oligohydramnios group and normal amniotic fluid group,with the increase of amniotic fluid,the incidence of neonatal complications decreased(P<0.05).There was no significant difference in neonatal complications among the three normal amniotic fluid subgroups(P>0.05).By using multivariate logistic regression analysis and adjusting age,gravidities,parities,BMI,gestational weeks,hypertensive disorders of pregnancy and diabetes mellitus,the results showed that oligohydramnios was an independent risk factor for preterm delivery,neonatal birth weight<2500g,neonatal admission,transfer to caesarean section and neonatal infection(a RR>1,P<0.05),and borderline oligohydramnios was an independent risk factor for selective cesarean section protective factors(a RR<1,P<0.05),and were independent risk factors for preterm delivery,labor induction and transfer to caesarean section(a RR>1,P<0.05).Conclusions 1 The rate of vaginal delivery with oligohydramnios decreased and the rate of transfer to caesarean section increased.Oligohydramnios is the cause of conversion to transfer to caesarean section.2 Newborns with oligohydramnios had the lowest birth weight,the highest rate of neonatal check in NICU and the longest hospitalization time of NICU.Oligohydramnios is the cause of premature delivery and neonatal infection.3 The labor induction rate of borderline oligohydramnios increased,and the conversion rate of transfer to caesarean section increased.Borderline oligohydramnios can lead to premature delivery.4 There was no difference in delivery mode and neonatal complications in the normal range of amniotic fluid.Figure 4;Table 13;Reference 123.